This proposal is a resubmission of an application for a 5-year renewal (Years 24-28) of an NRSA Institutional Research Grant for the training program in Cancer Epidemiology, Prevention, and Control at the Johns Hopkins Bloomberg School of Public Health. The program mission is to train pre-doctoral students and post-doctoral fellows to become leaders at the forefront of advancing the knowledge of the causes of cancer, including genetic and modifiable factors, and how to prevent cancer by providing a better understanding of cancer-related behaviors and identifying new markers for the early detection of cancer in population-based studies. The program goal is to create a rich and interactive environment for trainees augmented by the highly innovative, productive, and collaborative cancer research conducted by observational, basic, and clinical scientists at the School of Public Health, Kimmel Cancer Center, and Johns Hopkins Medical Institutions. The program themes are embodied in the 3 complementary training tracks: 1) Cancer Etiology and Prevention;2) Genetic Epidemiology of Cancer;and 3) Cancer Control. The 7 pre- and 4 post-doctoral trainees pursue a focused program consisting of shared elements across the tracks: didactic courses in substantive and methodologic issues within and across disciplines and research ethics;interactive information exchange including research in progress, seminars, and symposium;teaching, communication, grant writing experiences;practical experiences of a statistical analysis of an existing dataset and short rotations through epidemiology and laboratory cancer research programs (pre-doc);pre- or post-doctoral research under an engaged preceptor;and program-specific education, research, and career mentoring. We stress the importance of developing and testing novel biologically based hypotheses and collaborating across disciplines. Via the shared elements, our trainees are exposed to current issues, such as translational research, molecular epidemiology, emerging risk factors for cancers, methodologic issues in cancer research and screening, cancer disparities, tobacco control, obesity/energy balance, inflammation, and use of epidemiology in risk assessment and public policy. The revised program builds on a program with a long track record, with major changes made in response to evaluations from current and former trainees, an external advisor, and peer reviewers. The program has a core of 19 preceptors who are responsible for primary mentoring. An additional 39 affiliated faculty have committed in writing to providing expertise in specific cancer sites, biostatistics, and laboratory based exposure assessment;they were assembled to bring breadth and depth to the trainees'experiences and to meet their changing needs as science advances. A Steering Committee is responsible for trainee selection and monitoring, and refinement of the training program as these fields progress. The proposal documents a clear record of training and mentorship;the 23 pre- and 10 post-doctoral trainees appointed in the past 10 years have cancer research career success. From a large pool of applicants, we recruit the best possible candidates who represent diverse backgrounds. In summary, the program is designed to provide trainees with the multidisciplinary background essential to conduct the highest caliber state-of-the-art collaborative cancer research, to nurture innovative thinking and the ability to teach and communicate, and to prepare them to be leaders in the Nation's population-based cancer research agenda.